Connection Types - Pipes

Welding

Welding is a manufacturing process where parts/components are joined together through heat. Welding stainless steel is more difficult than other materials such as carbon steel because you need to exercise more care in temperature and choice of filler material [1][2].

• • • Tig welding to connect 2 pieces of stainless steel

    • Good sanitation of pieces if done correctly
    • Low amount of maintenance needed
    • Connection is permanent
    • High initial cost

Tri-Clamp

Tri-Clamp is a connection method first developed Alfa-Laval under the product name Tri-Clover. It functions by having two tri-clamp ends connected to aluminium pipes, a gasket to seal the two ends, and a clamp to lock everything into place [2].

• • • Used for tubing requiring high sanitation

    • Easy to install and seal
    • Common for food and beverage production
    • Does not leak before failure

Bevel Seat

Bevel Seat is a connection thread type that is very common in North America. It functions by having a male and female connector be joined together by a gasket, and tightened with a nut to seal [2].

• • • ACME Standards

    • Required special tooling wrench to tighten/loosen
    • Will leak before failure
    • Common thread type in Canada and the US

DIN

DIN is a threaded connector type first developed in Germany, and stands for Deutsche Industrial Norme. Like the Bevel Seat, it functions with a male and female connector, accompanied by a gasket and a nut to seal. The product however is more common in Europe and China [2].

• • • Used in food and beverage
      • Type 11850: Metric Standard
      • Type 11851: Imperial Standard
    • Required special tooling wrench to tighten/loosen
    • For German brewing, use metric standard DIN Type 11850
    • For North American piping, use imperial standard DIN Type 11851
    • Will leak before failure

SMS

A threaded connection type that is less common than DIN. But also functions with a male and female connector, accompanied by a gasket and a nut to seal. Originally developed in Sweden, SMS stands for Swedish Milk Standard [2].

• • • Required special tooling wrench to tighten/loosen
    • Common thread type in Europe and China
    • Will leak before failure

Cam and Groove

The Cam and Groove connection type is also called the Camlock fitting. It functions with a male end and a female end, and are mostly used for hosing connections [2].

• • • Easy to use and connect
    • No tools required for installation
    • Used for quick changing hoses
    • Used for home brewing as opposed to industrial usage
    • Used for hosing requiring low maintenance

NPT Thread

NPT Thread North American technical standard which stands for National Pipe Thread. It functions with a male end and a female end, and is more commonly used for non-sanitary piping rather than sanitary tubing [2].

• • • Material type requires different sealing aid
    • Fluid type requires different sealing aid
    • Requires a wrench to install or adjust
    • Can be permanent or temporary

Garden Hose Thread

Garden Hose Thread connectors are usually used for water applications such as wash down hoses. It functions with a male end and a female end, accompanied by a gasket [2].

• • • Slightly different than NPT Thread
    • 11.5 thread per inch
    • Inner diameter of 3/8", 1/2", 3/4"
    • Quick-release version available

Hose Barb

The Hose Barb connection allows for easy push-connection for stainless steel and elastic hoses. It functions with a male barb end and a female hose end, and is sometimes accompanied by a external clamp [2].

• • • Purposed to be permanent; can be temporary
    • Liquid and Gas applications
    • Good for connecting stainless steel to a flexible material
    • Usually lower operational pressures

Push to Connect

Push to Connect connection type is intended for use on hydraulic and pneumatic systems. It functions with a female port end, and a male hose end [2].

• • • Easy to install
    • Easy to uninstall/disconnect
    • Sizing is very important; hoses can pop through connection
    • Must accurately convert between metric and imperial
    • Used for processes: air/hydraulic fluid supply

Butt Fusion

Butt Fusions are usually used to ensure a permanent leak proof connection between individual lengths of piping. A machine can be used for quality Butt Fusions [12].

Procedure: (according to the Plastic Pipes Institute)

1. 1. 1. Clean, clamp, and align the pipe ends to be connected
      2. Face the pipe ends; establish clean, parallel surfaces perpendicular to the pipe centerline
      3. Align the pipe ends
      4. Melt the pipe interfaces
      5. Join the pipes together by contacting the melted ends, and apply adequate force
      6. Hold under pressure until the connection is cooled

Conventional Fusion

Conventional, or also known as Saddle Fusions are used to join a saddle to the side of a pipe. This method ensures a permanent leak proof connection, and requires that two ends: one concave, and one convex, to be heated prior to fusion. A machine is almost always used [12].

Procedure: (according to the Plastic Pipes Institute)

1. 1. 1. Clean the surface of the pipe where fusion is intended to be
      2. Install heater saddle adapter
      3. Install the saddle fusion machine on the pipe
      4. Align the parts
      5. Heat both the pipe and the saddle fitting
      6. Press and hold the two parts together
      7. Once the pieces are cooled and fused, remove the machine

Socket Fusion

Socket Fusions are formed when the external surface of the pipe end and the internal surface of the socket fitting are heated, and pushed to join together [12].

Procedure: (according to the Plastic Pipes Institute)

1. 1. 1. Clean the outer surface of the pipe end, and the inner surface of the fitting
      2. Square and prepare the pipe end
      3. Heat both the parts
      4. Join the parts through pushing and applying pressure
      5. Allow parts to cool and fuse

Electrofusion

Electrofusion is a type of heat fusion that differs because of the method by which heat is applied. In other words, instead of using a heating tool to heat the pipe and fitting surfaces, electrofusion internally heats joints by the use of a conductor or a conductive polymer. Given this, electrofusion requires a conductive material, and a electric current.

Procedure: (according to the Plastic Pipes Institute)

1. Prepare the pipe through scraping or cleaning
2. Mark the pipe
3. Align and restrain pipe and fitting based on manufacturer's specifications
4. Apply electric current
5. Cool and remove the clamps
6. Document the fusion process

References

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